Method and device for the production and filling of containers

ABSTRACT

The invention relates to a method for the production and filling of containers ( 12 ), whereby at least one tube ( 3 ) of plastified plastic material is extruded into an open mould ( 6 ), the tube ( 3 ) is bonded at the advancing end thereof on closing the mould ( 6 ) to give the container base and the tube ( 3 ) is severed above the mould, by a separating element ( 21 ) to give a filling opening. The mould ( 6 ) with the tube ( 3 ), comprising a filling opening, is moved to a filling position, in which the container is filled after the above is formed in the mould by means of generating an expanding pressure gradient acting on the tube ( 3 ). During the movement of the mould ( 6 ) into the filling position the filling opening of the tube ( 3 ) is covered by means of a sterile barrier ( 23 ).

[0001] The invention relates to a process for the production and fillingof containers having the characteristics specified in the preamble ofclaim 1. The invention also relates to a device for application of suchprocess having the characteristics specified in the preamble of claim 9.

[0002] A process of this type and device are described in U.S. Pat. No.5,962,039 and in JP-A-60049919. These processes of the state of the artpermit automated moulding (blow moulding or vacuum molding), filling,and sealing of vessels in a cost-effective manner. If highly sensitiveproducts are produced, ones such as pharmaceuticals for which theinternational standards relating to aseptic packaging are to be met, themould, when moved into the filling position, is positioned beneath aso-called sterile filling space (ASR), in which sterile air flows overthe open fill opening of the containers and creates effective protectionagainst entry of germs, until movable top jaws are closed aftercompletion of the filling process in order to form the desired top sealof the container by a combined vacuum-bonding process.

[0003] While the fill opening is effectively protected in the respectivestate-of-the-art processes and devices when this opening in the fillingposition by the sterile filling space, the uncovered fill opening is notfully protected during displacement of the mould from the extrusionposition, in which the tube formed is severed below the extruder nozzleand the fill opening, even if the process is conducted in a clean room.In other words, the tube having the fill opening forms a case open atthe top during movement of the mold into the filling position.

[0004] JP-A-4147824 has already proposed covering of the fill opening ofthe tube during movement of the mould into the filling position by aheatable cylinder and U.S. Pat. No. 5,261,545 has disclosed mounting ofa plate heatable by infrared above the fill opening in order to reducethe number of germs. However, even in these instances the fill openingis exposed, at least for a brief period, during change in the individualproduction positions, so that the danger exists that the interior of acontainer could be contaminated by germs or other particles.

[0005] On the basis of this state of the art the invention has theobject of providing a process and a device which in comparison ensureeven better protection of the open fill opening. In a process of thekind indicated above it is claimed for the invention that this object isattained by the characteristics specified in the descriptive portion ofclaim 1, and in the case of a device by the characteristics specified inthe descriptive portion of claim 9.

[0006] In that the sterile barrier is in the form of a heatable platewhich may be heated to a germ-killing temperature is movable togetherwith the separating element severing the tube, not only is the dangerprevented after severing of the hose of the possibility of foreignmatter falling into the open fill opening before the mould reaches thesterile filling space, the sterile barrier also blocks access by germsto the fill opening during this segment of the process. The processclaimed for the invention is accordingly suitable especially for theproduction of highly sensitive products for the medical/pharmaceuticalarea of application.

[0007] The sterile barrier is in the form of a heatable plate movabletogether with the separating element severing the tube, the plate beingheated to a germ-killing temperature, preferably above 150° C. In thatthe plate moves with the cutting edge severing the tube, the fillopening is covered by the heated plate even as the tube is being formed,that is, at no time is the fill opening uncovered.

[0008] Especially favorable conditions are established in this processif the separating element is in the form of a cutting edge which isimmediately adjacent to the heatable plate.

[0009] A cost-effective process with short cycle times is obtained ifthe heatable plate with the cutting edge for severance of the tubemounted on its leading edge is moved from a retracted initial positionto an operating position in a direction in which the plate is mountedabove the path of movement of the mould leading into the fillingposition, in such a way that the fill opening is covered by the platethroughout its travel to the filling position, and so that plate andcutting edge are then moved back from the operating position to theinitial position after the mould has reached the filling position.

[0010] Another object of the invention is development of a device forproduction and filling of containers having the features specified inclaim 9.

[0011] The invention is described in detail in what follows withreference to the drawing, in which

[0012]FIG. 1 presents a simplified diagram of an open blowing mould andan extrusion head positioned above it for forming a tube of plasticizedplastic;

[0013]FIG. 2 the partly closed blowing mould shown in FIG. 1 aftertransfer to a filling position and after formation of the container tobe filled; and

[0014] FIGS. 3 to 5 perspective views of greatly simplified diagramsillustrating the course of the process claimed for the invention.

[0015]FIGS. 1 and 2 illustrate an assembly such as is used within theframework of the conventional bottlepack® system for production ofplastic containers in the blow moulding process, a tube 3 of meltedplastic being extruded by means of an extruder assembly 1 between thetwo mould halves 5 of a mould 6, which is illustrated in FIG. 1. Afterextrusion of the tube 3 into the opened mould 6, the tube 3 is severedbetween the nozzle outlet of the extruder assembly 1 and the top of themould 6. In FIG. 1 the line of separation is shown as a broken line andis designated as 8. FIG. 2 shows the mould 6 in the partly closed state,the shaping components for the body of the container 12 to be mouldedfrom the tube 3, that is, the mould halves 5, being brought into contactwith each other so that the bottom bevel edges 7 on the lower end of thetube 3 execute a bonding process to seal the tube 3 to a bond seam 9(FIG. 2) on the bottom side.

[0016]FIG. 2 shows the mould 6 in a filling position in which the mouldhas been displaced, in contrast with the position illustrated in FIG. 1,laterally to the position toward the extruder assembly 1. In thisfilling position the container 12 which has previously been formed ischarged with content by way of the fill opening 15, blown air beingintroduced into the open fill opening 15 through by means of a blastarbor (not shown). FIG. 2 shows the end of the fill arbor 11 introducedinto the fill opening 15 for this purpose. Forming and charging of thecontainer may also be effected by means of a combined blast-fill arborin place of the fill arbor 11 and a previously introduced blast arbor.

[0017] In the filling position shown in FIG. 2, the mould is positionedbelow a so-called sterile filling space (ASR), which is not shown inFIG. 2 and which acts as aseptic shielding of the fill opening 15 whichis formed by the preceding severance process on the tube 3, along theline of separation 8 indicated in FIG. 1. After the container 12 hasbeen charged, the fill arbor 11 is moved away upward and the movable topbonding jaws 13, still open, of the mould 6 are brought together inorder to effect shaping on the container neck and/or to seal these jawssimultaneously by bonding. By means of the bonding jaws 13 illustratedin FIGS. 1 and 2 external threading is formed on the neck of thecontainer for a screw-on cap which may be provided in addition tosealing by bonding, for example, one in the form of a screw-on cap witha puncture pin in it.

[0018] FIGS. 3 to 5 illustrate by means of greatly simplified diagramsthe sequence of the process claimed for the invention on the basis of anexample in which, for the purpose of simultaneous production of twosmall-volume containers, two tubes 3 are extruded by means of theextruder assembly 1 into juxtaposed moulding cavities of the open mould6 (see FIG. 3), in which the mould 6 is indicated only by outlines ofthe mould halves 5, which may be moved in the directions indicated bythe double arrow 22 to open and close the mould).

[0019]FIG. 3 illustrates the operating state before severance of theextruded tubes 3, a heatable cutting edge 21 serving as separatingelement and a heatable plate 23 whose front edge is mounted so as to becontiguous with the cutting edge 21 being in the retracted initialposition. For the purpose of severing the tubes 6, plate 23 and cuttingedge 21, which may be moved back and forth in the directions indicatedby the double arrow 25, are moved from the initial position shown inFIG. 3 into the operating position (FIG. 4).

[0020] The heatable plate 23, whose surface consists of stainless steel,has imbedded in it a heating assembly (not shown) whose activity may becontrolled by means of temperature sensors 27. Together with the cuttingedge 21 the plate 23 is heated to a germ-killing temperature, preferablyone in the range above 200°, so that the plate 23 represents a sterilebarrier which is situated, when in the advanced operating position,above the openings 15 in the tubes 3 formed in the separation process.In the next step illustrated in FIG. 4, the mould 6 is now displacedfrom the extrusion position (FIG. 3) in the direction indicated by thedouble arrow 29 into the filling position shown in FIG. 4, the fillopenings 15 at the top of the mould 6 open at this time being positionedbelow the plate 23, which remain in the advanced operating position andaccordingly are covered by this sterile barrier. FIG. 4 illustrates theoperating state in which the mould 6 has reached the filling position,in which the fill openings 15 are now positioned below a sterile fillingspace 31. As is to be seen from FIG. 4, the plate 23 extends along thepath of movement of the mould 6 leading to the filling position farenough so that the entire area of this path of movement is covered, thatis, the fill openings 15 leave the area of plate 23 only when they haveentered the sterile filling space 31.

[0021] Only after this filling position has been reached are plate 23and cutting edge 21 again retracted from the advanced operating positionto the initial position, in which the cutting 21 edge in turn is in theinitial position for severance of the tubes 3 formed in the nextextrusion cycle (see FIG. 5).

[0022] The essential feature of the invention that the fill openingsformed in the process of severance of the extruded tubes are covered bya sterile barrier from the moment of their formation until the fillingposition protected by the sterile filling space 31 has been reached hasbeen explained in the foregoing on the basis of the example of aheatable plate 23 with a heatable cutting edge 21 positioned on itsfront side. It is to be noted that essentially use of a different kindof separating element and a heatable component forming a sterile barrierof a different configuration is also possible. Thus, for example, aheated wire may be provided in place of a knife-like cutting edge 21 orthe plate 23 could be replaced with a heatable, extremely close-meshedgrid with openings in the micrometer range. As is shown in FIGS. 3 to 5,the process may be applied for simultaneous production of a plurality ofcontainers, preferably containers of small volume in the form ofampules, or for production of container each of which may be producedindividually from a tube extruded in each operating cycle. Thecontainers may be formed by blow moulding or, specifically in the caseof containers of very small volume, by vacuum moulding.

1. A method for the production and filling of containers (12) in whichat least one tube (3) of plasticized plastic material is extruded intoan open mould (6), the tube (3) is bonded at its leading end when themould (6) is closed for the purpose of formation of the bottom of thecontainer, the tube (3) is severed above the mould (6) by means of aseparating element (21) for the purpose of forming a fill opening (15)and the mould (6) with the tube (3) having the fill opening (15) ismoved to a filling position in which the container (12) is filled afterit has been formed in the mould (6) by generation of a pressure gradientacting on and expanding the tube (3), the fill opening (15) of the tube(3) being covered by a sterile barrier (23) during movement of the mould(6) into the filling position, characterized in that the sterile barrieris formed by a heatable plate (23) movable together with the separatingelement (21) severing the tube (23), such heatable plate (23) beingheated to a germ-killing temperature.
 2. The process as claimed in claim1, wherein the heatable plate (23) is heated to a germ-killingtemperature higher than 150°.
 3. The process as claimed in claim 2,wherein the separating element is in the form of a cutting edge (21)which is immediately adjacent to the heatable plate (23).
 4. The processas claimed in claim 3, wherein the heatable plate (23) is moved,together with the cutting edge (21) mounted on its leading edge, for thepurpose of severance of the tube (3), from a retracted initial positioninto an operating position in a direction such that the plate (23) ispositioned above the path of movement of the mould (6) leading to thefilling position so that the fill opening (15) is covered by the plate(23) throughout its travel to the filling position, and wherein plate(23) and cutting edge (21) are then retracted from the operatingposition back to the initial position, after the mould (6) has reachedthe filling position.
 5. The process as claimed in one of claims 2 to 4,wherein the plate (23) is heated to a temperature higher than 170° C.,preferably to a temperature in the area of 200° C.
 6. The process asclaimed in one of claims 1 to 5, wherein more than one tube (3) ofplasticized plastic material is extruded into a multipart mould (6) forthe purpose of simultaneous production of a plurality of containers (12)and wherein the tubes (3) are severed together by the separating element(21).
 7. The process as claimed in one of claims 1 to 6, wherein a blowmould (6) is used as mould, one such that the pressure gradient actingon the tube (3) and expanding it to form the container (12) is generatedby delivery of blast air.
 8. The process as claimed in one of claims 1to 6, wherein a mould is used in which the pressure gradient acting onthe tube (3) and expanding it to form a container (12) is produced bynegative pressure generated between the mould walls and the exterior ofthe tube (3).
 9. A device for producing and filling containers (12),with at least one mould (6) having movable mould walls, into which mould(6) at least one tube (3) of plasticized plastic material may beextruded, whose mould parts (5) may be closed for the purpose of bondingthe projecting end of the tube (3) by means of the bevel edges (7)present on the mould parts (5) for the purpose of forming a containerbottom, with a device for generation of a pressure gradient acting onthe tube (3) and expanding it to form the container (12) on the mouldwalls, with a movable separating element (21) which may be moved betweena retracted initial position (FIG. 3) and an operating position (FIG. 4)for the purpose of forming a fill opening (45) for severance of the tube(3) above the mould (6), and with a displacement device for moving themould (6) into a filling position for filling the container (12) throughthe fill opening (15), a sterile barrier (23) being provided in such aposition which has dimensions such that it is positioned, when theseparating element (21) is in the operating position, above the path ofmovement of the mould (6) leading to the filling position and covers thefill opening (15), characterized in that a heatable plate (23) movabletogether with a cutting edge (21) serving as separating element isprovided as sterile barrier.
 10. The device as claimed in claim 9,wherein the cutting edge (21) is heatable and is mounted immediatelyadjacent to the projecting edge of the plate (23) and wherein such plate(23) is movable from its retracted initial position during severance ofthe tube (3) to its operating position covering the path of movement ofthe mould (6) in a direction extending transversely to the path ofmovement.
 11. A device as claimed in claim 9 or 10, wherein the heatableplate (23) has a heating device embedded in it and at least onetemperature measurement sensor (27) for control of the heating device.12. The device as claimed in claim 11, wherein the heatable plate (23)is of multilayer design and wherein at least the outer layers on theirbroad sides are made of stainless steel.